Wireless mobile communication networks continue to evolve given the increased traffic demands on the networks, the expanded coverage areas for service and the new systems being deployed. Cellular (“wireless”) communications networks rely on a network of base station antennas for connecting cellular devices, such as cellular telephones, to the wireless network. Many base station antennas include a plurality of radiating elements in a linear array. Various attributes of the antenna array, such as beam elevation angle, beam azimuth angle, and half power beam width may be adjusted by electrical-mechanical controllers. See, for example, U.S. Pat. Nos. 6,573,875 and 6,603,436, both of which are incorporated by reference. For example, with respect to U.S. Pat. No. 6,573,875, a plurality of radiating elements may be provided in an approximately vertical alignment. A feed network may be provided to supply each of the radiating elements with a signal. The phase angle of the signals provided to the radiating elements may be adjusted to cause a radiated beam angle produced by the antenna array to tilt up or down from a nominal or default beam angle.
Phase angles may be adjusted by mechanical phase shifters. In the example of the '875 patent, phase shifters are coupled by a common mechanical linkage. An expected phase angle may be ascertained from markings on a linkage rod or by a sensor in an electro-mechanical actuator located off the antenna panel extending beyond a bottom edge of the panel. However, markings on a linkage rod may not be determined remotely from the site, and known sensors in an electromechanical actuator typically comprise potentiometers. Furthermore, such potentiometers may have degraded performance as they age, and determine a position of the linkage, which for various reasons, may not necessarily be consistently correlated to a position of a phase shifter arm itself. What is needed is a more robust sensor which may be closely integrated into an electrical control circuit and which more directly measures the position of a phase shifter arm.
Also, previously known antenna arrays were known to have adjustable mounts which allowed default tilt angle to be set. In this arrangement, a mounting hardware allows the antenna array to be mechanically inclined with respect to a vertical axis to set a default phase angle (e.g., the angle at which a radiated beam would propagate if electrical tilt was set to zero). Default phase angle must be recorded during installation, and typically is, not remotely detectable.